Shocking (and forking)

Time for suspension fun. First order of business was to decide how much I wanted to lower the bike overall and then figure out how much of a spacer the forks would require. So I first measured the stock fork length, removed the forks springs, loosely assembled the front end, placed books of the correct thickness under the front wheel and then measured the fork length again. The difference was 1.25″ so I need to make a spacer of that thickness.

Question was, where does the spacer go? I thought it would simply go between the inner and outer fork tubes, but that’s not the case. “Warlordsix” has an excellent photo album on Photobucket that shows disassembly of the forks and with that as a guide I had them apart in short order. Once they were apart, it became apparent that I’ll need to disassemble the damper cartridge and insert the spacer there. I need to make a spanner in order to do that, so it’ll have to wait until then.

On all the various forums (ADV Rider, Thumpertalk, etc.), I read up on how to rebuild the WP 4681 BAVP shock as used on KTMs. Good stuff and quite helpful. One suggestion was to buy a cheap adjustable wrench, drill it for hardened pins and use it as a pin spanner to disassemble the seal head and reservoir. So, I bought a Harbor Freight 15″ adjustable wrench – made in India – steel should be soft right? Wrong. Hard enough that the tip broke off of my center punch. Took it to my friendly local machinist to let him do the job. Same thing. Even an end mill skittered across the surface. Hard stuff, I guess the British taught then how to heat-treat steel pretty well! My machinist friend just made two wrenches from scratch to do the job instead. In short order, the shock looked like this:

Overall it’s in pretty good condition, but the shaft seal was deteriorated and the bushing was quite worn. No biggie – the guys on ADV Rider said I could use a bushing and x-ring seal from McMaster-Carr and I had already bought them. Only problem was, my shock is somewhat different – first, there’s a retaining ring that has to be removed before the piston will come out of the body. Then, the seal isn’t a simple x-ring type, but metal-rubber composition type. Nothing I could find on McMaster-Car or anywhere else looked the same. The bushing looks the same, but is pressed into a sleeve not into the seal head itself. So, I decided to “bite the bullet” and spend $92 on the complete seal, o-ring and bushing kit from American Dirt Bike. Once that arrives and I’ve made the lowering bushing, reassembly can begin. Baby steps…

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